/**
* Copyright (c) By zengqh.
*
* This program is just for fun or demo, in the hope that it  
* will be useful, you can redistribute it and/or modify freely.
*
* Time: 2013/02/18
* File: matrix3x4.cpp
**/

#include "matrix3x4.h"

namespace HY
{
const Matrix3x4 Matrix3x4::ZERO(
	0.0f, 0.0f, 0.0f, 0.0f,
	0.0f, 0.0f, 0.0f, 0.0f,
	0.0f, 0.0f, 0.0f, 0.0f);

const Matrix3x4 Matrix3x4::IDENTITY(
	1.0f, 0.0f, 0.0f, 0.0f,
	0.0f, 1.0f, 0.0f, 0.0f,
	0.0f, 0.0f, 1.0f, 0.0f);

Matrix3x4::Matrix3x4(const Vector3& translation, const Quaternion& rotation, float scale)
{
	SetRotation(rotation.RotationMatrix() * scale);
	SetTranslation(translation);
}

Matrix3x4::Matrix3x4(const Vector3& translation, const Quaternion& rotation, const Vector3& scale)
{
	SetRotation(rotation.RotationMatrix().Scaled(scale));
	SetTranslation(translation);
}

void Matrix3x4::Decompose(Vector3& translation, Quaternion& rotation, Vector3& scale) const
{
	translation.x_ = m03_;
	translation.y_ = m13_;
	translation.z_ = m23_;

	scale.x_ = sqrtf(m00_ * m00_ + m10_ * m10_ + m20_ * m20_);
	scale.y_ = sqrtf(m01_ * m01_ + m11_ * m11_ + m21_ * m21_);
	scale.z_ = sqrtf(m02_ * m02_ + m12_ * m12_ + m22_ * m22_);

	Vector3 invScale(1.0f / scale.x_, 1.0f / scale.y_, 1.0f / scale.z_);
	rotation = Quaternion(ToMatrix3().Scaled(invScale));
}

Matrix3x4 Matrix3x4::Inverse() const
{
	float det = m00_ * m11_ * m22_ +
		m10_ * m21_ * m02_ +
		m20_ * m01_ * m12_ -
		m20_ * m11_ * m02_ -
		m10_ * m01_ * m22_ -
		m00_ * m21_ * m12_;

	float invDet = 1.0f / det;
	Matrix3x4 ret;

	ret.m00_ = (m11_ * m22_ - m21_ * m12_) * invDet;
	ret.m01_ = -(m01_ * m22_ - m21_ * m02_) * invDet;
	ret.m02_ = (m01_ * m12_ - m11_ * m02_) * invDet;
	ret.m03_ = -(m03_ * ret.m00_ + m13_ * ret.m01_ + m23_ * ret.m02_);
	ret.m10_ = -(m10_ * m22_ - m20_ * m12_) * invDet;
	ret.m11_ = (m00_ * m22_ - m20_ * m02_) * invDet;
	ret.m12_ = -(m00_ * m12_ - m10_ * m02_) * invDet;
	ret.m13_ = -(m03_ * ret.m10_ + m13_ * ret.m11_ + m23_ * ret.m12_);
	ret.m20_ = (m10_ * m21_ - m20_ * m11_) * invDet;
	ret.m21_ = -(m00_ * m21_ - m20_ * m01_) * invDet;
	ret.m22_ = (m00_ * m11_ - m10_ * m01_) * invDet;
	ret.m23_ = -(m03_ * ret.m20_ + m13_ * ret.m21_ + m23_ * ret.m22_);

	return ret;
}

}